Socioecology and Phylogeography of the Yellow-bellied Glider (Petaurus australis) Meredeth Brown (B.Soc.Sci., Hons) Environmental Biology School of Earth and Environmental Sciences The University of Adelaide South Australia A thesis submitted for the degree of Doctor of Philosophy at The University of Adelaide October 2006 Table of contents List of Tables v List of Figures vi Abstract viii Declaration ix Acknowledgements xii Dedication xv CHAPTER 1. GENERAL INTRODUCTION 1 1.1 Introduction and definitions 1 1.2 Social and mating systems 1 1.2.1 Monogamous social and mating systems 1 1.2.2 Inter- and intraspecific variation in social and mating systems 3 1.2.3 Use of DNA technologies in studies on behaviour 4 1.3 Reproductive ecology 4 1.3.1 Life history strategies in a seasonal environment 4 1.3.2 Seasonal conditions and forest phenology 6 1.4 Phylogeography and conservation units 7 1.4.1 Conservation units 7 1.5 The study species: the yellow-bellied glider (Petaurus australis) 9 1.5.1 Description of the study species 9 1.5.2 Distribution and conservation status 9 1.5.3 Social behaviour 10 1.5.4 Diet and reproductive behaviour 11 1.5.5 Variation between populations of yellow-bellied gliders 12 1.5.6 Management considerations of isolated populations 12 1.6 Aims of the thesis 13 CHAPTER 2. CHARACTERISATION AND OPTIMISATION OF MICROSATELLITE LOCI IN PETAURUS AUSTRALIS, P. BREVICEPS AND P. NORFOLCENSIS 14 2.1 Preamble 14 2.2 Introduction 14 2.3 Methods 15 2.4 Results and Conclusion 16 i CHAPTER 3. MONOGAMY IN THE YELLOW-BELLIED GLIDER 18 3.1 Preamble 18 3.2 Introduction 18 3.3 Methods 20 3.3.1 Study area and sampling times 20 3.3.2 Trapping and processing techniques 20 3.3.3 Collection and analysis of radio-tracking data 21 3.3.4 Observations of associations between paired adult males and females 23 3.3.5 Spatial distribution of den trees 23 3.3.6 Paternity analysis 24 3.4 Results 26 3.4.1 Home range overlap between individuals 26 3.4.2 Associations within adult male and female pairs 29 3.4.3 Distribution of den trees within the home range 30 3.4.4 Genetic analyses of parentage 31 3.5 Discussion 38 CHAPTER 4. FOREST PHENOLOGY AND THE TIMING OF REPRODUCTION IN THE YELLOW-BELLIED GLIDER 44 4.1 Preamble 44 4.2 Introduction 44 4.3 Materials and Methods 47 4.3.1 The study area 47 4.3.2 Trapping and processing techniques 48 4.3.3 Forest phenology 50 4.4 Results 52 4.4.1 Flowering phenology 52 4.4.2 Bark shed phenology 55 4.4.3 Timing of reproduction 57 4.5 Discussion 59 CHAPTER 5. PHYLOGEOGRAPHY OF THE YELLOW-BELLIED GLIDER 63 5.1 Preamble 63 5.2 Introduction 63 5.3 Materials and Methods 66 5.3.1 Tissue samples 66 5.3.2 mtDNA sequencing 67 5.3.3 mtDNA analyses 68 ii 5.3.4 Morphological measurements and analyses 69 5.4 Results 71 5.4.1 Variation and distribution of mtDNA haplotypes 71 5.4.2 Phylogeographic relationships of mtDNA haplotypes 73 5.4.3 Morphological data: sexual dimorphism and geographic variation 76 5.5 Discussion 77 5.5.1 Taxonomy 77 5.5.2 Conservation units and management 78 5.5.3 Levels of genetic variation 81 5.5.4 Phylogeography 82 5.5.5 Conclusions 82 CHAPTER 6. CONCLUDING DISCUSSION 83 6.1 Summary of aims 83 6.2 Mating system of yellow-bellied gliders 83 6.2.1 Evidence for a monogamous mating system 83 6.2.2 Factors contributing to monogamy in yellow-bellied gliders 84 6.2.3 Mate guarding or group sap feeding in yellow-bellied gliders? 85 6.3 Reproductive ecology of yellow-bellied gliders 86 6.3.1 Seasonality of food resources and aseasonality of births 86 6.3.2 Cues that may be important for initiating breeding in yellow-bellied gliders 86 6.3.3 Opportunism in the timing of breeding? 88 6.3.4 Aseasonality of births and a monogamous mating system 88 6.4 Conservation units in yellow-bellied gliders 89 6.4.1 ESU status of yellow-bellied gliders 89 6.5 Limitations to the study 89 6.6 Overall conclusion 90 List of appendices Appendix 1 92 Appendix 2 93 Appendix 3 97 Appendix 4(a)(b) 100 Appendix 5 103 Appendix 6 105 Appendix 7 107 Appendix 8 110 iii Appendix 9 111 Appendix 10 112 References 115 Publications 132 iv List of tables Table 2.1 Polymorphic microsatellite loci isolated from Petaurus breviceps (Petb1, 4, 6, 7, 8 and 9) and P. australis (Peta13, 16 and 18), including the primer sequence (F, forward; R, reverse), core repeat motif, size of alleles (bp), number of alleles at each locus, observed (Ho) and expected (He) heterozygosities* (information on allele size, no. of alleles and heterozygosity for Petb1, 4, 6, 7, 8 and 9 is for P. breviceps; Peta13, 16 and 18 is for P. australis) and GenBank Accession numbers. Petb6(a) primers were designed for specific amplification of the Petb6 locus in P. australis. 17 Table 3.1 Amount of overlap (%) for cohabiting males and females, and between adjacent territories. Overlap is calculated from MCP 100% home ranges of each individual. Mean SE and range, in parentheses, is presented. n = number of overlaps observed. Monogamous pairs = one male cohabiting with one female. Polygynous/ polyterritorial group = one male overlapped his home range with those of two females. 29 Table 3.3 Likelihood analysis for putative mothers based on 10,000 simulations where no adults were assigned as known parents. LOD scores and Delta statistics for the female putative parent for each juvenile are provided. Putative mothers are in order of most likely candidate as defined by CERVUS. Delta statistics are between the most likely candidate mother and the next most likely candidate mother. ID numbers are the DNA in alcohol numbers assigned by the Evolutionary Biology Unit, SA Museum. #=juveniles/subadults where the social mother was not known, ^=true mother did not return a positive LOD score. *=95% and +=80% confidence interval, NS=not significant. 32 Table 3.4 Likelihood analysis for putative fathers based on 10,000 simulations where no parent was assumed and where the social mother was assigned the known parent. LOD scores and Delta statistics of each putative father are provided. Putative fathers are in order of most likely candidate as defined by CERVUS. Delta statistics are between the most likely candidate father and the next most likely father. *=95% and +=80% confidence interval, NS=not significant. #=subadults that were assigned by Cervus the most likely female candidate. 35 Table 5.1 Numbers of samples (n), haplotypes and diversity indices standard deviation (gene and nucleotide diversity estimated using ARLEQUIN v.3.01) in populations of yellow-bellied gliders. 72 Table 5.2 Within and between regions pairwise distance (HKY85 model) comparisons. Mean standard deviation and range (in parentheses) are shown as percentages. Within regions comparisons are on the diagonal, between regions comparisons are above the diagonal. 72 v List of figures Fig. 3.1 (a) Yellow-bellied gliders home ranges using MCP 100% (female home ranges are in bold outline, whilst male home ranges are in fine outline); and (b) home ranges using Kernel 50% (all core home ranges are in black) and 90%; female home ranges are in white, males are in grey (the darker grey showing the adult male in C group). Group names are indicated on MCP 100% home ranges but are also applicable to Kernel home ranges. Kernel home ranges are circled to make group identification easier. The location of a home range for the adult male and female in group B is indicated by the dashed arrow (prior to the disappearance of both the adult male and female after August 2002). The adult male and one adult female from C group resided in this area from August/September 2002 until the end of the study in August 2003. The forest is bordered by Pinus radiata plantations on the west, but continuous native habitat exists to the north, south and east. 28 Fig. 3.2 Interindividual distances of monogamous pairs (cohabiting adult male and adult female) and a polygynous group (one adult male and two adult females). Monogamous pairs (n = 4 pairs) are compared with polygynous group (n = 1 group). Distance classes contain 25m ranges. Total number of observations = 117. 30 Fig. 4.1 Monthly mean daily maximum and minimum temperatures and average monthly rainfall for Rennick. Temperature data from 1948 to 2001 from the Australian Government Bureau of Meteorology, http://www.bom.gov.au/climate/averages/tables/cw_090092.shtml. Rainfall data from 1953 to 2003 from Hancock Victorian Timber Plantations. 48 Fig. 4.2 Circular distributions of the number of (a) manna gum and (b) brown stringybark monitored trees in flower for both years combined. Number of trees in flower is indicated on the N-S, E-W axes. The length of each wedge is representative of the number of trees in flower for that month. The bold line emerging from the centre to the edge is the mean, whilst the arcs on the outside of the circle are the 95% confidence limits of the mean. 53 Fig. 4.3 Number of monitored (a) manna gum and (b) brown stringybark trees in various phases of flowering. Trees were categorised as having <1,000 flowers (light), between 1,001 and 10,000 (medium) flowers, and 10,001 (heavy) flowers.